HOW TO COUNT KINKS - FROM THE CONTINUUM TO THE LATTICE AND BACK

We investigate the matching between (1+1)-dimensional nonlinear field theories coupled to an external stochastic environment and their latti ce simulations. In particular, we focus on how to obtain numerical res ults which are lattice-spacing independent, and on how to extract the correct effective potential which emerges from the simulations. As an application, we study the thermal production of kink-antikink pairs, o btaining a number density of pairs which is lattice-spacing independen t and the effective barrier for pair production, i.e., the effective k ink mass. (C) 1998 Elsevier Science B.V.